Mary Haynes was born in Townsend, Massachusetts on July 11, 1841 to Samuel Haynes and Eliza Spaulding Haynes. She attended public and private schools in Townsend and Groton, Massachusetts, then taught in Townsend and New Ipswich, New Hampshire. In 1861 she entered Mount Holyoke Female Seminary and graduated in 1864. She taught at Mount Holyoke from 1864-1868. She married the Reverend John William Lane, a Congregational minister, on August 26, 1868. They had eight children, three of whom died in infancy. She and her husband also took two Chinese children into their home and educated them along with their own children. From 1868-1877 they lived in Whately, Massachusetts and later moved to North Hadley, Massachusetts where her husband took charge of a congregation. Upon her husband's death in 1911, she went to live with her daughter, Mrs. Amy Powell in Springfield, Massachusetts. She remained there until her own death on June 25, 1922, at the age of eighty.